Initial patch to make the MIT KDB backend for HDB handle multiple kvnos.

This commit is contained in:
Nicolas Williams
2011-07-13 00:24:42 -05:00
committed by Nicolas Williams
parent 34bb7ae363
commit e7f385ad0d

View File

@@ -196,12 +196,226 @@ fix_salt(krb5_context context, hdb_entry *ent, int key_num)
return 0;
}
/**
* This function outputs a pointer to a Key or array of @key_count Keys
* where the caller may place Keys.
*
* @param context Context
* @param entry HDB entry
* @param kvno kvno of the keys to be added
* @param is_hist Whether the keys will be historical keys or current keys
* @param key_count Size of array of keys to set. MUST be zero if !is_hist.
* @param out Pointer to Key * variable where to put the resulting Key *
*
* See three call sites below for more information.
*/
static krb5_error_code
get_entry_key_location(krb5_context context, hdb_entry *entry, krb5_kvno kvno,
krb5_boolean is_hist, size_t key_count, Key **out)
{
HDB_extension ext;
HDB_Ext_KeySet *hist_keys;
hdb_keyset *keyset = NULL;
size_t keyset_count = 0;
Key *k = NULL;
size_t i;
krb5_error_code ret;
*out = NULL;
if (!is_hist) {
Key *tmp;
/* Extend current keyset */
tmp = realloc(entry->keys.val, sizeof(entry->keys.val[0]) * (entry->keys.len + 1));
if (tmp == NULL) {
ret = ENOMEM;
goto out;
}
entry->keys.val = tmp;
/* k points to current Key */
k = &entry->keys.val[entry->keys.len];
memset(k, 0, sizeof(*k));
entry->keys.len += 1;
goto done;
}
/* Find a history keyset and extend it or extend the history keyset */
memset(&ext, 0, sizeof (ext));
ext.data.element = choice_HDB_extension_data_hist_keys;
hist_keys = &ext.data.u.hist_keys;
/* hdb_replace_extension() makes a copy of ext */
ret = hdb_replace_extension(context, entry, &ext);
if (ret)
return ret;
for (i = 0; i < hist_keys->len; i++) {
if (hist_keys->val[i].kvno == kvno) {
/* We're adding a key to an existing history keyset */
keyset = &hist_keys->val[i];
if ((keyset->keys.len % 8) == 0) {
Key *tmp;
/* We're adding the 9th, 17th, ... key to the set */
tmp = realloc(keyset->keys.val,
(keyset->keys.len + 8) * sizeof (*tmp));
if (tmp == NULL) {
ret = ENOMEM;
goto out;
}
}
break;
}
}
if (keyset == NULL) {
/* We're adding the first key of a new history keyset */
if (hist_keys->val == NULL) {
if (key_count == 0)
keyset_count = 8; /* There's not that many enctypes */
else
keyset_count = key_count;
hist_keys->val = calloc(keyset_count,
sizeof (*hist_keys->val));
if (hist_keys->val == NULL) {
ret = ENOMEM;
goto out;
}
keyset = &hist_keys->val[0];
} else if (hist_keys->len == keyset_count) {
hdb_keyset *tmp;
keyset_count *= 2;
tmp = realloc(hist_keys->val,
keyset_count * sizeof (*hist_keys->val));
if (tmp == NULL) {
ret = ENOMEM;
goto out;
}
hist_keys->val = tmp;
}
}
k = &keyset->keys.val[keyset->keys.len];
if (key_count != 0)
keyset->keys.len += key_count;
done:
memset(k, 0, sizeof (*k));
k->mkvno = malloc(sizeof(*k->mkvno));
if (k->mkvno == NULL) {
ret = ENOMEM;
goto out;
}
*k->mkvno = 1;
*out = k;
out:
if (ret && !is_hist)
entry->keys.len--;
if (is_hist)
free_HDB_extension(&ext);
return ret;
}
/**
* This function takes a key from a krb5_storage from an MIT KDB encoded
* entry and places it in the given Key object.
*
* @param context Context
* @param entry HDB entry
* @param sp krb5_storage with current offset set to the beginning of a
* key
* @param version See comments in caller body for the backstory on this
* @param k Key * to load the key into
*/
static krb5_error_code
mdb_keyvalue2key(krb5_context context, hdb_entry *entry, krb5_storage *sp, uint16_t version, Key *k)
{
size_t i;
uint16_t u16, type;
krb5_error_code ret;
for (i = 0; i < version; i++) {
CHECK(ret = krb5_ret_uint16(sp, &type));
CHECK(ret = krb5_ret_uint16(sp, &u16));
if (i == 0) {
/* This "version" means we have a key */
k->key.keytype = type;
if (u16 < 2) {
ret = EINVAL;
goto out;
}
/*
* MIT stores keys encrypted keys as {16-bit length
* of plaintext key, {encrypted key}}. The reason
* for this is that the Kerberos cryptosystem is not
* length-preserving. Heimdal's approach is to
* truncate the plaintext to the expected length of
* the key given its enctype, so we ignore this
* 16-bit length-of-plaintext-key field.
*/
krb5_storage_seek(sp, 2, SEEK_CUR); /* skip real length */
k->key.keyvalue.length = u16 - 2; /* adjust cipher len */
k->key.keyvalue.data = malloc(k->key.keyvalue.length);
krb5_storage_read(sp, k->key.keyvalue.data,
k->key.keyvalue.length);
} else if (i == 1) {
/* This "version" means we have a salt */
k->salt = calloc(1, sizeof(*k->salt));
if (k->salt == NULL) {
ret = ENOMEM;
goto out;
}
k->salt->type = type;
if (u16 != 0) {
k->salt->salt.data = malloc(u16);
if (k->salt->salt.data == NULL) {
ret = ENOMEM;
goto out;
}
k->salt->salt.length = u16;
krb5_storage_read(sp, k->salt->salt.data, k->salt->salt.length);
}
fix_salt(context, entry, entry->keys.len - 1);
} else {
/*
* Whatever this "version" might be, we skip it
*
* XXX A krb5.conf parameter requesting that we log
* about strangeness like this, or return an error
* from here, might be nice.
*/
krb5_storage_seek(sp, u16, SEEK_CUR);
}
}
return 0;
out:
free_Key(k);
memset(k, 0, sizeof (*k));
return ret;
}
/**
* This function parses an MIT krb5 encoded KDB entry and fills in the
* given HDB entry with it.
*/
static krb5_error_code
mdb_value2entry(krb5_context context, krb5_data *data, krb5_kvno kvno, hdb_entry *entry)
{
krb5_error_code ret;
krb5_storage *sp;
Key *k;
krb5_kvno key_kvno;
uint32_t u32;
uint16_t u16, num_keys, num_tl;
size_t i, j;
@@ -328,125 +542,63 @@ mdb_value2entry(krb5_context context, krb5_data *data, krb5_kvno kvno, hdb_entry
for (i = 0; i < num_keys; i++) {
int keep = 0;
uint16_t version;
void *ptr;
CHECK(ret = krb5_ret_uint16(sp, &u16));
version = u16;
CHECK(ret = krb5_ret_uint16(sp, &u16));
key_kvno = u16;
/*
* First time through, and until we find one matching key,
* entry->kvno == 0.
*/
if ((entry->kvno < u16) && (kvno == 0 || kvno == u16)) {
keep = 1;
entry->kvno = u16;
if ((entry->kvno < key_kvno) && (kvno == 0 || kvno == key_kvno)) {
/*
* Found a higher kvno than earlier, so free the old highest
* kvno keys.
*
* XXX Of course, we actually want to extract the old kvnos
* as well, for some of the kadm5 APIs. We shouldn't free
* these keys, but keep them elsewhere.
* Found a higher kvno than earlier, we aren't looking for
* any particular kvno, so save the previously saved keys as
* historical keys.
*/
keep = 1;
/* Get an array of Keys to save the current keyset into */
ret = get_entry_key_location(context, entry, entry->kvno, TRUE,
entry->keys.len, &k);
for (j = 0; j < entry->keys.len; j++)
copy_Key(&entry->keys.val[j], &k[j]);
/* Change the entry's current kvno */
entry->kvno = key_kvno;
for (j = 0; j < entry->keys.len; j++)
free_Key(&entry->keys.val[j]);
free(entry->keys.val);
entry->keys.len = 0;
entry->keys.val = NULL;
} else if (entry->kvno == u16)
} else if (entry->kvno == key_kvno)
/* Accumulate keys */
keep = 1;
if (keep) {
Key *k;
ptr = realloc(entry->keys.val, sizeof(entry->keys.val[0]) * (entry->keys.len + 1));
if (ptr == NULL) {
ret = ENOMEM;
ret = get_entry_key_location(context, entry, key_kvno,
FALSE, 0, &k);
if (ret)
goto out;
}
entry->keys.val = ptr;
/* k points to current Key */
k = &entry->keys.val[entry->keys.len];
memset(k, 0, sizeof(*k));
entry->keys.len += 1;
k->mkvno = malloc(sizeof(*k->mkvno));
if (k->mkvno == NULL) {
ret = ENOMEM;
ret = mdb_keyvalue2key(context, entry, sp, version, k);
if (ret)
goto out;
}
*k->mkvno = 1;
for (j = 0; j < version; j++) {
uint16_t type;
CHECK(ret = krb5_ret_uint16(sp, &type));
CHECK(ret = krb5_ret_uint16(sp, &u16));
if (j == 0) {
/* This "version" means we have a key */
k->key.keytype = type;
if (u16 < 2) {
ret = EINVAL;
goto out;
}
/*
* MIT stores keys encrypted keys as {16-bit length
* of plaintext key, {encrypted key}}. The reason
* for this is that the Kerberos cryptosystem is not
* length-preserving. Heimdal's approach is to
* truncate the plaintext to the expected length of
* the key given its enctype, so we ignore this
* 16-bit length-of-plaintext-key field.
*/
krb5_storage_seek(sp, 2, SEEK_CUR); /* skip real length */
k->key.keyvalue.length = u16 - 2; /* adjust cipher len */
k->key.keyvalue.data = malloc(k->key.keyvalue.length);
krb5_storage_read(sp, k->key.keyvalue.data,
k->key.keyvalue.length);
} else if (j == 1) {
/* This "version" means we have a salt */
k->salt = calloc(1, sizeof(*k->salt));
if (k->salt == NULL) {
ret = ENOMEM;
goto out;
}
k->salt->type = type;
if (u16 != 0) {
k->salt->salt.data = malloc(u16);
if (k->salt->salt.data == NULL) {
ret = ENOMEM;
goto out;
}
k->salt->salt.length = u16;
krb5_storage_read(sp, k->salt->salt.data, k->salt->salt.length);
}
fix_salt(context, entry, entry->keys.len - 1);
} else {
/*
* Whatever this "version" might be, we skip it
*
* XXX A krb5.conf parameter requesting that we log
* about strangeness like this, or return an error
* from here, might be nice.
*/
krb5_storage_seek(sp, u16, SEEK_CUR);
}
}
} else {
/*
* XXX For now we skip older kvnos, but we should extract
* them...
* them... XXX Finish.
*/
for (j = 0; j < version; j++) {
/* enctype */
CHECK(ret = krb5_ret_uint16(sp, &u16));
/* encrypted key (or plaintext salt) */
CHECK(ret = krb5_ret_uint16(sp, &u16));
krb5_storage_seek(sp, u16, SEEK_CUR);
}
ret = get_entry_key_location(context, entry, key_kvno, TRUE, 0, &k);
if (ret)
goto out;
ret = mdb_keyvalue2key(context, entry, sp, version, k);
if (ret)
goto out;
}
}
@@ -581,19 +733,25 @@ static krb5_error_code
mdb_rename(krb5_context context, HDB *db, const char *new_name)
{
int ret;
char *old, *new;
char *old = NULL;
char *new = NULL;
asprintf(&old, "%s.db", db->hdb_name);
asprintf(&new, "%s.db", new_name);
if (asprintf(&old, "%s.db", db->hdb_name) < 0)
goto out;
if (asprintf(&new, "%s.db", new_name) < 0)
goto out;
ret = rename(old, new);
free(old);
free(new);
if(ret)
return errno;
goto out;
free(db->hdb_name);
db->hdb_name = strdup(new_name);
return 0;
errno = 0;
out:
free(old);
free(new);
return errno;
}
static krb5_error_code
@@ -732,8 +890,7 @@ mdb_open(krb5_context context, HDB *db, int flags, mode_t mode)
char *fn;
krb5_error_code ret;
asprintf(&fn, "%s.db", db->hdb_name);
if (fn == NULL) {
if (asprintf(&fn, "%s.db", db->hdb_name) < 0) {
krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
return ENOMEM;
}